可注射性骨修复材料不饱和聚磷酸酯的光引发交联聚合

通过凝胶含量的测定,研究了紫外光引发不饱和聚磷酸酯(UPPE)与 N-乙烯基吡咯烷酮的共聚交联反应.结果表明:加入光引发剂能够显著增加凝胶含量,安息香乙醚(BE),安息香(BN),2,2-二乙氧基苯乙酮的引发活性较高.光引发剂浓度较低时,增加光引发剂的含量能够显著提高单位时间内的凝胶生成率,但含量过大反而降低凝胶生成率.BN、BE的适宜浓度分别为2.4E^-5(mol/g UPPE)及0.6E^-5(mol/g UPPE).光照较短时间内,UPPE分子量为5960 g/mol的体系具有最高的凝胶生成率,但由于粘度的影响,光照2 min后其凝胶生成率低于UPPE分子量为4040 g/mol的体系.表层对紫外光的吸收降低了光能量,导致深层交联聚合反应速度降低,1.5 mm厚试样通过延长曝光时间,凝胶含量可与1.0 mm厚试样接近,6.0 mm试样曝光24 min后底层仍不能固化.

Photocrosslinking Behavior of Unsaturated Polyphosphoester Used as An Injectable Bone Repair Material

The UV crosslinking reaction of unsaturated polyphosphoester with N-vinyl pyrrolidone was investigated by gel content measurement. The experiment results show that photoinitiators can remarkably improve the gel content of curing product. Among all initiators used in this study, BE, BN and DEAP show high initiating activities. The gel content of curing product increased with the increasing of initiator amount within low concentration, but higher concentration of photoinitiator would reduce the gel content. The optimum amount of BN and BE was 2.4E-5(mol/g UPPE)and 0.6E-5(mol/g UPPE), respectively. The gel content of crosslinked network obtained from unsaturated polyphosphoester with Mw = 4040 g·mol-1 is lower than that of with higher molecular weight when the irradiation time was less than 2 minutes, but an opposite results would obtained by extending irradiation time. The surface layer of sample absorbed the UV light and decreased the pho-tocrosslinking reaction rate of the deep layer. Gel content of the sample with 1.5 mm in thickness would approach to that of sample with 1. 0 mm in thickness by extending irradiation time. The crosslinking reaction was uncompleted for the sample with 6.0 mm in thickness after 24 min irradiation.